Set non-CPU limits for pods to work well with Karpenter.

 1apiVersion: kyverno.io/v1
 2kind: ClusterPolicy
 3metadata:
 4  name: set-karpenter-non-cpu-limits
 5  annotations:
 6    policies.kyverno.io/title: Set non-CPU limits for pods to work well with Karpenter.
 7    policies.kyverno.io/subject: Pod
 8    policies.kyverno.io/category: Karpenter, EKS Best Practices
 9    policies.kyverno.io/severity: medium
10    kyverno.io/kyverno-version: 1.9.3
11    kyverno.io/kubernetes-version: "1.26"
12    policies.kyverno.io/minversion: 1.6.0
13    policies.kyverno.io/description: >-
14      For correct node provisioning Karpenter should know exactly what the non-CPU resources are 
15      that the pods will need. Otherwise Karpenter will put as many pods on a node as possible, 
16      which may lead to memory pressure on nodes. This is especially important in consolidation 
17      mode.
18spec:
19  rules:
20    - name: set-ephemeral-storage
21      match:
22        any:
23          - resources:
24              kinds:
25                - Pod
26      mutate:
27        foreach:
28          - list: request.object.spec.containers
29            patchStrategicMerge:
30              spec:
31                containers:
32                  - (name): "{{element.name}}"
33                    resources:
34                      limits:
35                        +(ephemeral-storage): "{{element.resources.limits.\"ephemeral-storage\" || element.resources.requests.\"ephemeral-storage\"}}"
36                      requests:
37                        ephemeral-storage: "{{element.resources.limits.\"ephemeral-storage\" || element.resources.requests.\"ephemeral-storage\"}}"
38    - name: set-memory
39      match:
40        any:
41          - resources:
42              kinds:
43                - Pod
44      mutate:
45        foreach:
46          - list: request.object.spec.containers
47            patchStrategicMerge:
48              spec:
49                containers:
50                  - (name): "{{element.name}}"
51                    resources:
52                      limits:
53                        +(memory): "{{element.resources.limits.memory || element.resources.requests.memory}}"
54                      requests:
55                        memory: "{{element.resources.limits.memory || element.resources.requests.memory}}"